One in Ten Lives with a Rare Disease

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February 28 is Rare Disease Day — a concept first initiated by the European Rare Disease Organization (EURORDIS) and now recognized around the world. Around 6,800 rare diseases have been identified and up to 80% of them have a genetic origin. 23andMe provides genetic health reports for many of these conditions and also carries out research on a few of them.

When it comes to rare diseases, rare is not actually that rare.

Take that one person with cystic fibrosis, the other person with sarcoma, and then someone with sickle cell anemia. All of these conditions are considered rare, but when you add up all the people with a rare disease you land at “one in ten.” This means that roughly 30 million Americans suffer from a rare disease.

Definitions can vary, but in the United States the “rare” label is applied to any condition that affects fewer than 200,000 individuals, or roughly one in 1500. Rare diseases are often poorly understood, with symptoms that can be difficult to diagnose, and can be life-threatening.

Most rare diseases can’t be cured and many lack effective treatments because research is often hampered by a scarcity of study participants and poor funding. 23andMe hopes to change this.

Our Myeloproliferative Neoplasms and Sarcoma research initiatives are aimed at understanding what causes these conditions, information that may one day help bring about a cure.

Beyond these initiatives we also research rare diseases through the typical customer experience. Individuals come to 23andMe, receive their genetic results, and if they desire, contribute to research by providing information about themselves. Our scientists aggregate this information and draw interesting correlations.

A first-glance finding is that roughly nine percent of 23andMe customers have a rare disease, right on par with the national average of ten percent. Slightly more 23andMe individuals with a rare disease are women.



  • K Lau

    What are these diseases? Is there a few more common ones? If there are common ones, they are not rare.
    I have two basic questions about this survey. (1) would people with rare disease tends to answer this question and hence over inflate the percentage. (2) my idea of a rare disease is not necessary the same as yours. How does 23andMe ensure that a reasonable definition is used across all the responders?

    • BethannH

      A full list of rare conditions can be found on the National Organization of Rare Diseases’ website: http://www.rarediseases.org/rare-disease-information/rare-diseases. The 23andMe survey simply asked customers if they have a rare disease. Many people who have been diagnosed with a rare disease know that their disease is rare. That said, you raise a good point that some people may have answered that they have a rare disease when actually their condition is not that rare.

  • Stewart Fakelastname

    Isn’t there a sample bias here? I’d expect that people with rare diseases would be much more likely to use genetic testing services such as 23&me.

    • BethannH

      Hello Stewart,
      It’s an interesting question. The national average is 1/10 and 23andMe reports 1/11 with a rare disease. It certainly seems possible that people with a rare disease might be more interested in using genetic testing services.

  • Chris

    I would imagine that there is a sample bias as people with a history of illness, whether a rare disease or not, will be more interested in joining 23&Me than the general population.

  • Scott23H

    Valmae,
    I do not think we are doing any research around that condition. However we hope to be doing some work around IBD and ulcerative colitis, which is linked to the condition.

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